Paddle-powered watercraft such as kayaks and stand-up paddle boards have long been used for water transportation and recreation. The prior art includes sail devices that can be attached to these watercraft and/or to their paddles for propulsion by wind, when conditions are favorable, in addition to propulsion by conventional paddling.
One prior art arrangement is disclosed in U.S. Pat. No. 6,986,318, issued to Sawyer, and entitled Sail Assembly. This patent is representative of disadvantageous aspects of prior art sail devices. These disadvantageous aspects may include that the devices:                are bulky;        have multiple movable parts and/or fastener components;        are heavy when wet, particularly the canvas or fabric sails;        are problematic to stow when not in use; and        interfere with proper and convenient use of the paddle in the stowed position (see for example FIGS. 5-6 of Sawyer, i.e., ready and comfortable use of the paddle is obstructed by the stowed sail).        
A need thus exists for a roll out sail for use with a longitudinal paddle or pole shaft that is (1) thin and streamline; (2) exceptionally light weight; (3) made of substantially non-water absorbing material; (4) has no or minimal moving parts and/or components; (5) when stowed, does not interfere with use of the paddle or pole shaft; and/or (6) is stowable in a manner that it becomes the hand-hold for the shaft (and thus may appear to the use as the actual shaft, without closer inspection).
Another disadvantageous aspect of prior art paddle sail devices is that they are effective only for downwind travel. There is a need for a sail and/or paddle and sail arrangement that has effective cross-wind and upwind capabilities.
There is also a need to provide wind propulsion to any mode of manual transportation—kayaking, pole-push skateboarding, etc.—that utilizes a propulsion device having a shaft or similar structure on which a sail may be compactly stowed.